Lead pointing machine



June 27, 1961 A. OSMUNDSEN LEAD POINTING MACHINE Filed July 31. 1958 N m E. 5 mmflwm WW w MM IMN 5 w .w F m United States Patent 2,989,947 LEAD POINTING MACHINE Arnold Osmundsen, 355 Lincoln Ave., 'Clifiside Park, NJ. Filed July 31, 1958, Ser. No. 752,265 '3 Claims. (Cl. 120-96) This invention relates to a machine for pointing the lead of wood and mechanical drafting pencils normally used by architects, engineers and draftsmen.

In prior art manual and electrically operated pencil sharpeners have been made. These pencil sharpeners cut the wood, exposing the lead, and thereby sharpening it.

Furthermore, lead pointers have been made whereby the operator had to twist, twirl or rub the lead) against the abrasive material, or insert the lead into a machine and rotate the lead against an abrasive material thereby pointing same.

An object of the present invention is to improve these prior art devices through the provision of a machine wherein the operator is not required to twist, twirl or rub the lead against the abrasive material.

Another object of this invention is the provision of a machine which will point the lead of pencils in a clean and eifective manner.

A further object of this invention is the provision of a portable machine which will point the lead varying from a blunt to a needle point as desired, depending upon the length of lead exposed from the Wood or mechanical drafting pencil.

Yet another object is to provide a motor driven pointing device which rotates around the lead.

A still further object is to provide a portable machine having means which will automatically close the electric circuit when the pencil is inserted into the machine and automatically open the electric circuit when the pencil is removed.

Other objects and advantages of the present invention will become apparent in the course of the following specification.

In accomplishing the objects of the present invention it was found desirable to provide a portable machine wherein only the lead comes in contact with the abrasive pointer; consequently most expensive mechanical drafting pencils can be used with this machine without the fear of wear or damage to them. The machine of the present invention does not cut, nor does it remove the wood from wood pencils, but it does point the lead of the pencil after the wood has been cut back with a knife or special wood cutter. This machine comprises a housing containing an electro-motor and provided with an interchangeable pencil guide. The insertion of a pencil through the guide actuates a switch which turns on the motor. The rotation of the motor produces a tilting of an abrasive pointer which is pressed against the lead of the pencil by the centrifugal force. when the lead is pointed, the pencil is removed and the switch is thereby caused to turn ofi the motor.

The invention will appear more clearly from the following description when taken in connection with the accompanying drawing showing, by way of example, a preferred embodiment of the inventive idea.

In the drawing:

FIGURE 1 is a top View of a lead pointing machlne constructed in accordance with the principles of the present invention.

FIGURE 2 is a front View.

FIGURE 3 is a sectional view along the line 33 of FIGURES 1 and 2.

FIGURE 4 is a perspective view of the interchangeable pencil guide.

FIGURE 5 is a sectional view on an enlarged scale along the line 5-5 of FIGURES l and 2.

2,989,947 Patented June 27, 1961 FIGURE 6 is an exploded perspective view of the abrasive pointer and holder assembly.

FIGURE 7 is a diagrammatic view of the pencil switch assembly and electric circuit.

The lead pointing machine shown in the drawing comprises a housing which includes a body 25 and a block 23 fastened to the body 25 by screws 26 and 27 and carrying an interchangeable pencil guide 2 provided with an orifice 1 for the insertion of the pencil. Several pencil guides 2 having orifices 1 of diiferent diameters may be made to accommodate the various pencils which are being manufactured. A conducting bottom plate 18 is firmly connected with the body 25 and carries an insulating non-skid base 28 which is glued to the plate 18. The block 23 has a pencil stop 3 which is in alinement with the orifice 1 of the guide 2.

A felt pad 13 which is used to wipe off any dust which may adhere to the lead is fixed upon an outer surface of the body 25.

The pencil guide 2 has a slot 24 which is adapted to receive a portion of a switch spring 7. The spring 7 is mounted in a wall of the block 23 and its inoperative position within the slot 24 is indicated in full lines in FIG- URE 5. Broken lines designated by the numeral 8 show the operative position of the spring 7 when it is pushed out of the slot 24 by a pencil to be pointed and is brought into engagement with a switch pin 9.

An electro-motor 10 is located within the body 25 and is enclosed by a motor cover 29 which is attached to the motor 19 by a screw 30. A motor mount block 34 is attached by screws 22 and 33 to the motor 10 and to a plate constituting a part of the block 23.

The screw 22 is electrically conducting and it electrically connects the motor 10 with an extension of the spring 7.

The motor 19 has a motor shaft 11 which is enclosed by a dust retainer 31. The dust retainer 31 is held against the motor cover 29 by a holder 12 which in turn is held to the motor shaft 11 by a set screw 32.

An abrasive L-shaped pointer 4 is swingably mounted upon a pivot or carriage screw 5 which is carried by the holder 12.

Referring to FIGURES 3, 5 and 7, the electrical circuit of the machine includes the pencil switch spring 7 which in the position 8, makes contact with switch pin 9 onto which is soldered an insulated conductor 15, which in turn is fastened to a contact spring 16 which makes contact with a battery 17. The conducting bottom plate 18 electrically connects the battery 17 with a battery 19 which is conductively connected with a contact spring 20. An insulated conductor 21 connects the contact spring 20 with the motor 10 and the motor mount screw 22 completes the circuit to the pencil switch spring 7.

The operation of the device is as follows:

Referring to FIGURE 5, the lead is pointed by simply inserting the pencil into the orifice I of the interchangeable pencil guide 2 until it hits the stop 3. In doing so, the lead strikes the abrasive pointer 4 causing it to tilt about the axis of the carriage screw 5 and come to rest in a position indicated by broken linm 6. The pencil causes the pencil switch spring 7 to depress to the position 8 making contact with the switch pin 9. This completes the circuit and energizes the motor 19, causing the motor shaft 11, the holder 12 and the pointer 4 to rotate. The centrifugal force produced by the rotation will cause the abrasive pointer 4 in the position 6 to press against the lead, pointing same as the pointer 4 endeavors to return to its original position indicated by full lines in FIGURE 5.

When the lead is pointed, the operator will hear and/ or feel the speed of the motor increase. He should then remove the pencil which will permit the pencil switch spring 7 to return to its original position, thereby opening the circuit and shutting oflf the flow of current to the motor 10.

The abrasive pointer 4 may be constructed in a number of different Ways. For example, the entire pointer may be shaped or formed of abrasive cutting material. However, the pointer may be formed or shaped of metal or plastic, on to which surface 14 is fused an abrasive material (FIGURE 6). Furthermore, a replaceable abrasive material having a backing of paper, cloth or a combination of paper and cloth, may be laminated upon the surface 14. In addition, the pointer may be formed or shaped of metal in which the surface '14 is double or triple smooth cut, such as a file.

Numerous other changes may be also made within the scope of the present invention. For example, in lieu of the two batteries17 and 19, the machine of the present invention will operate on electrical energy produced by one or a combination of batteries connected in a series or a parallel circuit, or the batteries may be omitted and electrical energy produced by other means which may be substituted along with the proper type of motor. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A lead pointing machine, comprising a housing, a pencil guide carried by said housing, an electro-motor located within said housing, said housing having a pencil stop located between the inner end of said pencil guide and said motor, a switching device operatively connected with said motor and having a portion located in the path of a pencil inserted into said pencil guide for switching on said motor when engaged by said pencil, an L-shaped pointer having an abrasive leg portion located adjacent to the lead of a pencil engaging said pencil stop, another leg portion extending substantially perpendicularly to the first-mentioned leg portion, a pivot swingably supporting said abrasive pointer substantially intermediate said leg portions, a motor shaft driven by said motor, and a holder operatively connected with said motor shaft and carrying said pivot, said abrasive pointer having a surface engaging the lead of said pencil when said motor is switched on to point said lead.

2. A machine in accordance with claim 1, wherein said surface of the abrasive pointer consists of an abrasive material.

3. A machine in accordance with claim 2, wherein said surface constitutes a removable and replaceable portion of said abrasive pointer.

References Cited in the'file of this patent UNITED STATES PATENTS 836,712 Rush Nov. 27, 1906 2,288,407 Lada June 30, 1942 2,657,672 Angell Nov. 3, 1953 2,851,009 Branvold Sept. 9, 1958 FOREIGN PATENTS 614,946 Great Britain Dec. 30, 194-8 

